Expanding drill or reamer



April 29, 1930. s. 1 A CAMPBELL EXPANDI'N-G 'DRILL OR BEAMER Filed Feb. 14, T928 Patented Apro 29, 193() STEWART L. CBELL, 0F BERKELEY, CALIFORNIA, ASSIGNOR T0 JOEE GT, OIF

LOS ANGELES, CALIFORNIA EXPANDING DRILL 0R BEAMER This invention has relation to collapsible and expansible drilling tools, and although the vinvention is peculiarly applicable t0 a drill bit of the sh-tail or similar type, and will be explained particularly with regard thereto, it is also applicable generally to expansible reamers, as will be pointed out.

A general object of the invention is the provision of a simple and strong expansible construction for a drilling tool of the type that utilizes acutting element in the form of a iiat blade typically such as the blade of a fish-tail bit. In the ordinary non-expansible fish-tail bit this blade is usually one single piece, but according to my invention l" divide the blade into two-parts or half blades which are then so mounted as to be relativel rotatable about a common center and pre erablyrelatively rotatable about the vertical center of the tool. And preferably one of the half blades, or cutting elements as l shall call them, may be 'formed integrally with the tool body, the relative swinging motion taking place by virtue of swinging movement of the other cutting element or blade about the body center.

How the invention is carried out in a practical design and how it may be made appli cable to reamers, etc., will be best understood 'from the following detailed description. it will be understood that this description is intended only to set out in particular detail a present preferred and illustrative embodiment of the invention and is not to be taken as a limitation upon the invention except as expressly so stated in the appended claims.

For the purposes of descri tion i refer to the accompanying drawings in which Figure 1 is a side elevation ot an expansive fish-tail bit showing the tool in its expanded position.

Figure 2 is a rcentral vertical section talren in the same aspect as Figure 1.

Figure 3 is a view similar to Figure 1, but showing a simple modification adapting the tool to use as 'a reamer.

Figure 4 is a bottom view of the tool shown Figure 6 is a cross-section on line 6-6 of Figure 1.

Figure 7 is a similar cross-section showing the tool contracted.

Figure 8 is a cross section on the line 8-8 ot Figure 1.

Figure 9 is a similar cross section showing the tool contracted. l

Figure 10 is an edge view of the tool shown in Figure 1.

in the drawings l show a suitable body at 10 and a cutting element 11, inthe form of a half fish-tail blade, formed integrally or connected integrally at its upperl end with body 10. The formation and contour of element 11\may be designed to suit any Aparticular type of work. i show. the element substantially in a form corresponding to onehalt1 of the usual sh-tail blade except that the inner or central edge of the halt blade 11 is provided with certain recesses and projections to be hereinafter described.

The other half 'of the iish-tail vblade is formed by the relatively movable cutting element 12 which is shown as being substantially similar to elementll in contour and shape, so that when the two half blades 11 and 12 are assembled in their expanded relative positions they form in e'ect the whole sh-tail bit. The half blade or element 12, however, is not made integral with body 10, but is mounted with respect to that body and with respect to element 11 so vthat it may swing between the relative positions shown in Figures l and 5.

'Co provide a pivot on which element-,'12 may swing-1 preferably provide a central pivot mandrel. 13 which is formed integrally with and depends from a sub 14. This sub has the usual taper-threaded pin 15 at its upper end for connection with a drill stem and at its lower end and at the, upper end lof the pivot mandrely 13 it has another taperthreaded pin Y16 which screws into a corresponding taper-threaded socket in the upper end of the body.

The two adjacent inner edges of elements 11 and 12 are formed with inter-en aging extensions and notches 20 and 21 as will best be seen from an inspection et Figure 2.

These extensions 20 form in edect hinge-eyes, andthe pivot mandrel 13 extends down through the parts 20 to form in effect the hinge pin between the two parts 11 and 12 and to form a pivot upon which the part 12 swings. In the particular design here shown the element 12 has two such extensions lor hinge eyes 20 spaced vertically from each other, while the element 11 has but one such extension or hinge eye 20 located between the two extensions 20 of element 12. The pivot mandrel 13 may be steppeddown in diameter -as it passes downwardly through minimizing the liability of the tool becoming clogged or balled up with mud. This feature of the design will be well understood from the edge elevation of Figure 10.

The support aiorded the lower end ofthe pivot mandrel 13 where it passes through the extension 2O of element 11 greatly strengthens the pivot mandrel-and prevents its breakage or distortion. The two spaced bearings of element 12 upon the pivot mandrel give that ele-ment a comparatively long vertical extent of bearing and insure its rigid support against any forces tending to twist it out of proper vertical alinement.

In order to limit the relative swinging movement of element 12 suitable stops are provided. These stops may be provided in a variety of manners', but I prefer .here to show such stops applied to the upper end of element 12 and also applied to points near its lower end.` Thus, 4at its upper end the element 12 may have a stop lug 25, in the form of a sector as is most clearly shown in Figures 8 and 9. This sector plays in a recess 26 which is cut or otherwise formed in the lower surface of body 10 and is here lsa shown as semi-circular in extent. The radial shoulders 27 and y28 at the ends of recess 26 form the stops against which sector 25 brings up when element 12 reaches its limiting positions. Thus, as shown in Figure 3, where the stop sector 25 is up against shoulder 27, the

l two elements 11 and 12 extend diametrically f opposite each other and form in edect a coinmeaaoe tool, which is smaller in diameter than circle H, can then bear directly against one side of the hole or casing and the two projecting cuttrelenients 11 and 12 are both loca-ted at or'near the opposite side of the hole or casing. Thus, in Figure 5 the circle at C indicates the interior size of a casing through which the collapsed tool may be passed; and the circle H is'again shown for comparison with circle C.

Additional stops for the swinging motion of element 12 may be provided near its lower end. Thus, the lowermost extension or hinge eye 2O of element 12 may carry a stop extension 3() which, in the expanded position shown in Figure 6, brings up against element 11; and furthermore element 12 may have still another stop near its lower end in the form of a stop lug 31 which swings around against the face 'of elementll when the parts are in expanded position. This is best shown in Figures i and 5.

I have now described the invention particularly as an expansive andcontractive fishtailbit, but by reference to Figure 3 the adaptability of the invention to use as a reamer or the like will be readily understood. In`

fact the only essential diierence between the tool as a lish-tail'bit and the tool as a reamer is in this, that when used as a drilling bit it has its cutting edges, or at least its major cutting edges, at the lower ends ofthe cutting element (in the form shown in Figure 1 these cutting edges will usually be merely sharp edges along the lower ends of elements 11 and 12) while in the reamer form the cutting edges are placed along the lateral vertical edges of the elements 11 and 12. Thus the form ot Figure 1 may be readily made into a reamer suitable for certain kinds of formation merely by sharpening theouter vertical edges of elements 11 and 12. But in Figure 3 li show those outer vertical edges equipped with roller reaming cutters 35 adapted particularly for reaming operations to ream out a hole `which has already been drilled either by another tool or by the samev tool, and the tool here described may lend itself very readily to performing simultaneously the drilling and reaming operations,

the lower sharpened edges 36 of elements 11 and 12, or 11* and 12al of Figure 3, drilling a hole of a certain size ahead of the reaming cutters 35, and the reaming cutters 35 then reaming the hole out to the desired larger diameter.

actual or ultimate cutters; and this will be understood when I refer to the parts 11 and 12 as being cutting elements.l

Expansive and contractive movement of the parts of this expansive tool ma be wholly or partially accomplished by re ative rotations as above described. However, longitudinal movement of the tool up'agamst the lower end of the casing may either act solely to cause contractive movement or may act in conjunction with left-handed rotation to. cause contractive movement. For this purpose the upper `corners of elements 11 and 12 may be beveledr as shown at 4() so that when the tool is drawn up against the lower end of the casing, and as soon as element-12 has pivot mandrel.

vat the lowermost hinge lug 20 land is thus moved slightly from its ullyexpanded posi: tion, then the pressure of the casing end upon the beveled face 40 will tend to swing element -12 around toward element 11-in other words, will tend to swing the two elements around toward each other.

The sub 14 and pivot mandrel 13 may be provided with a central water course 50 to deliver circulating fluid to the lower end of the This 'lower end is located located fairly close to the lower cutting edges of elements 11 and 12. The water or other fluid delivered through the passage 50 will thus be delivered centrally of the two elements 11 and 12 and near their lower ends and directly into the slight gap 51 between their adjacent inner edges.

I claim 1. In an expansive tool of the character described, a substantially cylindric body, a cutting element integral with the body and ly ing substantially in a plane radial to the central vertical axis of the body, a central pivdt mandrel extending down through and below the body and screw-threadedly mounted therein, the inner edge of said cutting element having a bearing lug through which the lower part of ,the pivot mandrel passes and by -which it is supported, another cutting element lyingvsubstantially in a plane radial to said central-vertical axis and having spaced bearing lugs surrounding the pivot mandrel,

whereby said last mentioned cutting element is swingingly supported upon the' pivot mandrel to swing about the central'vertical axis of the body.

2. In an expansive tool of the character described, a substantially cylindric body, a cutting element integral with the body and lying substantially in a plane radial to the central vertical axis of the body, acentral pivot mandrel extending down through and below the body and screw-threadedly mounted therein,

the inner edge of said cutting element having a bearing lug through which the lower part of the pivot mandrel passes and by which it is supported, another cutting element lying substantially in a plane radial to said central vertical axis and having spaced bearing lugs surrounding the pivot mandrel, whereby said last mentioned cutting element is swingingly supported upon the pivot mandrel to swing about the central vertical axis of the body,

the outerv edges of both cutting elements exface of the body.

3. In an expansive tool of the character described, a substantially cylindricbody, a cutting element integral with the body and lying substantially in a plane radial to the central vertical axis of the body, al central pivot man` drel extending down through and below the tending horizontally'beyond the exterior surbody and screw-threadedly mounted therein, Y

the inner edge of said cuttlng element having a bearin lug through which the lower part of the pivot mandrel passes and by which it is supported, another cutting element lying substantially in aplane radial to said central vertical axis and having spaced.l bearing lugs surrounding the pivot mandrel, whereby said last mentioned cutting element is swingingly supported upon the pivot mandrel to swing about the lcentral vertical axis of the body, a s'topl lug'mounted on the upper end of the last mentioned cutting element, and the body having a lug receiving recess oflimited extent to allow limited swinging movement of said stop lug and 'of the swmging cutting element. f

4. 'In an expansive tool of the character described, a central vertical pivot mandrel, a pair of cutting elements mounted on said pivot mandrel, and standing substantially in planes radial to its vertical center, one of sald elements bei-ng relatively rotatable about the center of the pivot mandrel between a position diametrically opposed to the other element and a position in which both elements -are at one side of the pivot mandrel.

yand positions in which said elements stand both at the samer side of the pivot mandrel. l 6. In an expansivevtool of the character described, a central vertical pivot mandrel, a pair of cutting elements'mounted on said pivot mandrel, and:` standing substantially in planes radial to its vertical center, one of tion in which both cuttin arcanos" v elements are at said elements being relatively rotatable about one side of the pivot man rel.

vthe centerI of the'pivot mandrel between a po- In witness that 1 claim the foregoing I sition diametrically opposed to the other elehave hereunto subscribed my name this 27 are at one side of the pivot mandrel, said cut- -ting elements extending below the'lower end 0f the pivot mandrel, and the pivotmandrel having a central vertical circulation passage adapted to deliver iiuid from its lower end centrally between the lower ends of the two elements.

7; In an expansive tool of the character described, a substantially cylindric body, a cutting element integral with the body, depending therefrom, and lying substantially in a plane radial to the central vertical axis of the body, a central pivot mandrel extending down through and below the body and non-rotatively mounted in the body, another cutting element lying substantially in a plane radial to said central vertical axis and swingingly mounted at its inner edge on the pivot mandrel, whereby said last mentioned cutting element is swingingly supported upon the pivot mandrel to swing about the central vertical axis of the body.

' 8./In an expansive tool of the character described, a substantially cylindric body, a

cutting element integral with the body, depending therefrom, and lying substantially in a plane radial to the central vertical axis of the body, a central pivot mandrel extending down through and below the body and non-rotatively mounted in the body, the lower part of the pivot mandrel havmg a sup'- v port bearing on the inner part of said cutting element, another cutting element lying A substantially in a plane radial to said central vertical axis and swingingly mounted at its inner edge on the pivot mandrel, whereby said last mentioned cutting element is swingingly supported upon the pivot mandrel to swing about the central vertical axis o`f'thev body.

s 9. In, an expansive tool of the character described, a substantially cylindric body, a cutting element integral with the body, depending therefrom, and lying substantially in a plane radial to the central vertical axis of the body, a central ivot mandrel extending down through an below the body and n'on-rotatively mounted in the body, another cutting element lying substantially in a plane radial to said central vertical axis and swingingly mounted at its inner edge on the pivot mandrel, whereby said last mentioned lcutting element is swingingly supported upon the pivot mandrel to swing about the central vertical axis of the body, and stops limiting tioned cuttingI element between a position substantially diametrically opposed to the i iirst mentioned cutting element and a posiu ment and a position in which both elements day of January, 1928. 

